The Gastroenterology Division of the Department of Medicine (GI Division), in collaboration with Center for Clinical Epidemiology and Biostatistics (CCEB), both of the University of Pennsylvania (Penn) School of Medicine, and Penn's Leonard Davis Institute of Health Economics (LDI), submits this application to continue an innovative and successful post-doctoral training program for clinical investigators in gastrointestinal clinical research. Penn promotes an academic environment in which basic and clinical research are encouraged and viewed as attractive career paths. This training program attracts gastroenterology trainees from institutions nationwide; its graduates are placed in institutions nationwide, resulting in a program of high impact. The two- to three-year training program consists of: 1) required courses in clinical epidemiology, health services research, biostatistics, and gastroenterology epidemiology; 2) elective courses relevant to the trainees' methodologic interests; 3) a research apprenticeship; 4) journal clubs and conferences focusing on research issues in gastroenterology; 5) extensive independent readings; 6) a professional and career development seminar series; and 7) instruction in the responsible conduct of research. The coursework, readings, apprenticeship, and seminars are designed to prepare trainees for the major component on the training program: the design and completion of a mentored but trainee led research project in gastroenterology. The program: 1) trains clinicians to be rigorous and independent academic investigators able to use a broad array of clinical research methods to address research issues in gastroenterology related to the etiology, prognosis, prevention, early detection, treatment, clinical economics, technology assessment, medical decision making, and quality of patient care; 2) provides a closely mentored research experience with faculty preceptors in clinical research and gastroenterology; and 3) strengthens the links between clinical research and gastroenterology. Four fellowship slots are awarded each year. Trainees will matriculate in either the Master of Science in Clinical Epidemiology (MSCE) or Master of Science in Health Policy Research (MSHPR) degree program. Strengths of the proposed program are: 1) the long history of successful research training programs in the GI Division, CCEB, and LDI; 2) the collaborative links that already have been forged among the three programs; 3) the comprehensive course offerings and ongoing research programs available to trainees; and 4) the successful training records of the program directors and faculty. In addition, the availability of the broad range of rich expertise of the faculties in the GI Division, CCEB, an LDI; numerous existing large databases that can be used for research projects and training; a broad array of specialized analytic capabilities available for clinical studies (e.g., clinical trils, case-control, cohort research, etc.); and the faculties' commitment to collaborative research and training combine to provide an ideal environment for this training program.